This invention relates to a conditioned air system for buildings.
This invention further relates to a diffuser unit for a conditioned air system, and in particular to a ceiling mounted diffuser unit for a conditioned air system which delivers a modulated, variable volume of conditioned air to a room or other space in the building in response to changes in the temperature of the air in that room or other space which it conditions.
The invention also relates to an integrated sensor actuator which both senses temperature changes in the room and also provides the actuating force for varying the amount of air flow into the room in response to the sensed temperature. The integrated sensor actuator generates the actuating force for varying the volume of air flow without the use of any external or auxiliary systems or apparatus, (such as pneumatic air, duct pressure or electrical or hydraulic powered apparatus) for supplying the force necessary to vary the volume of air flow.
The invention also relates to a diffuser construction which directs the outflowing air from the diffuser into the room and along the adjacent ceiling surfaces at an efficient aerodynamic angle and velocity so as to cause the air to hug the ceiling and to minimize the problems of dumping of cold air in the parts of the room adjacent and below the diffuser.
The invention also relates to a diffuser which is constructed to operate on a low pressure differential to minimize noise and to conserve power and energy of the related conditioned air system.
Dumping of cold air from a ceiling mounted outlet for a ceiling mounted conditioned air system has been a problem in the prior art. If the cooling air does not leave the ceiling outlet with sufficient velocity or at the proper angle of flow, the result can be large temperature differentials between different areas and different levels in the room, and this can produce noticeable discomfort for the people in the room.
Most conditioned air distribution systems are set up to vary either the volume or the temperature of the conditioned air flow in response to a measurement of the temperature in the room. If the volume of the conditioned air flow is varied, the system is known as a variable air volume system (in the terminology of the art). Many current installations of conditioned air systems are using variable air volume systems (rather than constant volume, variable temperature systems) because the variable air volume system offers a number of potential operating and cost advantages.
The conventional practice in the prior art has been to modulate the volume flow of conditioned air in response to the air temperature in the room to which the conditioned air is supplied. In most such cases, a thermostat is used to sense the air temperature, and the thermostat is connected to an actuator system for positioning a damper in the branch duct supplying the conditioned air outlet device for the room. The temperature sensing mechanism is usually located in a position which is remote from the conditioned air outlet, and an auxiliary system or apparatus (such as an pneumatically powered actuator or an electrically powered or in some cases and hydraulicly powered actuator) is used to reposition the damper with changes in the room air temperature.
There are also actuating systems used in the prior art which are called self contained systems, but such systems are self contained in the sense only that they use the duct pressure to power and reposition the damper.
These prior art systems have presented a number of problems. They have been somewhat complex because of the need to interconnect the remotely located thermostat with the actuator apparatus. And the auxiliary actuator apparatus has in itself often contributed unfavorably to the complexity and size and cost of the system.
It is a primary object of the present invention to avoid and to overcome the problems of the prior art as described above.
It is a closely related object to construct an individually controlled, self contained, variable air volume diffuser which incorporates, as an integral part of the diffuser, a unitary sensor actuator that is directly powered by the temperature of the air in the room and that does not require any auxiliary actuator system or apparatus for varying the volume flow of conditioned air through the diffuser in response to changes in the sensed room air temperature.